Consulting past exceptions to facilitate workflow exception handling

In this paper, we propose an architecture model that deals with both expected and unexpected exceptions in the context of workflow management. Expected exceptions and their handling approaches are specified by ECA rules, while cases of unexpected exceptions are characterized by their features and resolution approaches. The handling of unexpected exceptions is then assisted by the system providing information about how recent similar cases were resolved. The ways in which the previous exception cases were handled provides useful information in determining how to handle the current one. Quantifying the similarity of exception cases is described, and three algorithms for efficiently searching for similar exception cases are proposed and evaluated both theoretically and by experimenting with synthetic data sets. (C) 2002 Elsevier B.V. All rights reserved.